yashinon

Hi,

I am looking at getting my Son to ride with me. He is 5'4", therefore I thought that a 49/50 CM frame would fit him. The LBS had a 49 CM road bike. However, the associate recommended going with a 52CM frame size (Of course there is no stock in that size). The reason being extension of the legs while pedaling (something like that).

The LBS did not have pedals on the bike in stock, therefore it could not be tested. However, I am wondering now if 49 CM will fit just fine.

Thanks!

CliffordK

How old is he, and how tall are Mom & Pop?

Casual riding, or racing?

I'm been trying to keep up with bicycles for my nephew as he was growing like a weed. He's now about 6'2", four inches taller than me, and potentially still growing.

I would encourage you to buy the bike for the size you expect your kid to be next year. So, if he can ride the 52, get that one.

Unfortunately, with stocking issues around the country, there may be benefits of getting him on what you can actually BUY.

PeteHski

I can only imagine it must have been obviously too small if they didn't try to sell you the bike they had in stock!

yashinon

I ride a 52cm and I am 5'6". I just want to make sure that get a bike that fits properly.

bruce19

Forget height. Measure your inseam in CM. Roughly 2/3 of that will put you in the ballpark for frame size. Having said that, the proportionality of your body dimensions can make a difference. My inseam is 32.5" in CM that's 82.55. So, my frame size should be around 55. My body is pretty proportional so a 55 with 55 TT is perfect for me. And, has been for 40 years.

seypat

If he's going to grow some more get a used bike from your CL. The growth spurts can go through 2 or 3 sizes in a couple of months.

CliffordK

Ok, so he'll probably not become a giant in the future.

I'd still probably go a bit on the larger size for growth, but that still is the range of bikes you're looking at.

Has the kid ridden your bicycle if it is the size you're looking for?

terrymorse 

At 5'4", your son probably can squeeze onto a 52 cm frame, but it's not the ideal size for that height.

If he's still growing, and he can handle the standover height with any room to spare, go for it.

He's certainly need a short stem, but that's not the worst thing in the world.

(My frame height formula: cyclist height in inches minus 14 = frame size in centimeters, so his ideal frame size would be 64 - 14 = 50 cm.)

urbanknight

I just bought a 49cm road bike for my 4'10" son and just had to put a 60mm stem to make it fit. My mother is 5'0" and rides a 50cm. I could definitely see your son fitting a 52cm, MAYBE needing a slightly shorter stem. It sounds like he's going to grow a few more inches anyway.

That being said, if a 52 is that hard to come by (and/or you don't want to buy a bike without testing it), a 49/50 can probably be made to fit your son just fine. If leg extension is really an issue, you can probably get a longer and more setback seatpost.

yashinon

Nope, he is an adult - so very unlikely.

yashinon

Thanks! I think it is best to go ride the bikes. I was swayed by the associate at the LBS and there were no pedals on the bike. Will keep looking.

jon c. 

As someone else noted, it is unusual for a bike shop to tell you that the bike they don't have would be better than the bike they do have. Especially in a case where the one they do have is closer to the default recommendation.

I can't imagine a bike shop not having pedals for a test ride.

I wouldn't buy anything you can't test ride first.

urbanknight

Ah, in that case it wouldn’t hurt to see if the smaller bike can be made to fit (maybe longer setback seat post and/or a longer stem), but considering he’s not likely to change height, it’s best to get the exact right size if you can.

Russ Roth

At 5'2" I'd think a 49cm should be fine and would shy away from a 52cm. Wife has a friend who wants to get into road riding and doesn't have a road bike, the wife wants to sell hers to the friend. Only issue is the friend is 5'4" and the bike is 52cm, I think it'll be an OK fit and will have her try it but it is currently adjusted to my 5'6" wife. I agree with TerryMorse's chart though and find it aligns with all the purchases I've made for my family.

CliffordK

An important detail you left out earlier.

Go try out the 49 or 50 the bike shop has in stock.

And, let the kid also try your 52.

mstateglfr 

The shop had no access to some basic platform pedals?
Thats...odd.